In the transportation industry, a common problem is that a distributed communication bus system may be electrically connected to many generic nodes. When a distributed communication bus interconnects many generic nodes, it is difficult to assign a unique address to each node within the distributed system. Due to the difficulty of uniquely addressing many generic nodes intercoupled together, many electrical systems within transportation applications individually program each node or component before placement within the system. By changing each IC or node before placement into the system, each node can be uniquely identified easily, but such advantage comes at a cost. When devices are programmed with an address before assembly, human error may result in the improper placement of a device programmed as "Device A" into an improper location intended for a "Device B" whereby faulty operation can occur. This faulty operation may not be capable of easy and cost-effective testing, as is the case for the testing of airbag systems in an automobile. In addition, the overhead for keeping track of individually addressed parts before assembly can be cumbersome. For example, assume that sixteen generic parts are desired in the same communication bus system. If these sixteen parts are generic, then all sixteen parts may be catalogued, stored, and used as one interchangeable part. If an individual tag must be applied to each of the sixteen generic parts, then the process of storing, reusing, repairing, replacing, and assembling the systems becomes much more cumbersome and prone to human error.
As an alternative to uniquely tagging parts before assembly, one may use uniquely configured sockets or physical interconnects for the parts to make each generic part uniquely identifiable. While different in form from the above pre-programmed solution, the disadvantages and risks are the same.
Alternatively, a distributed communication bus system may be avoided in favor of a point-to-point communication system where each of N nodes is directly coupled to a central controller by a respective one of N different and mutually exclusive conductors. This ensures that each node can be uniquely accessed; however, there are many disadvantages to this approach. These N conductive interconnects can quickly become cumbersome within a transportation design, and the costs of such design may be prohibitive. The added interconnection of additional wire will significantly add to the weight of the system or automobile. The interconnection density in an automobile chassis is limited and better dedicated to other more important functions. In addition, N connections may need N pins on an IC, where pin count is severely limited in many microcontroller and digital signal processor (DSP) designs. In general, this brute force method of connecting unique lines to each node in the system is fast becoming unreasonable.
Generally, a need exists in the transportation industry, and others, for a distributed communication bus architecture and methodology which enables generic nodes or components to be intercoupled via a common communication bus connection where unique addressing or tagging of the generic components is still enabled.